In modern society, the development of the communications industry makes the relationship between people more and more closer. Terminals like cell phones and tablet computers have become main devices for people to communicate between each other, and people rely more and more on these terminals. Taking the cell phone as an example, the existing cell phone can communicate with other cell phones or tablet computers only through a subscriber identity card, e.g., a Subscriber Identity Module (SIM) card, and each SIM card has a unique number. If a user leaves the cell phone at home (the cell phone left at home is called the original cell phone hereinafter), then the user cannot use another cell phone and the phone number of the original cell phone to make a call, and other cell phones cannot reach the user by calling the phone number of the original cell phone. If the user loses the cell phone as well as the SIM card, then the user has to renew the SIM card of the phone number to use the original phone number to communicate with other users. It can be concluded that there is a problem during the use of a cell phone, that is, it is impossible to use the phone number of the original cell phone to establish communication with other devices when the user forgets to carry or loses the cell phone.